# Boeing Alert Service Bulletin 747-53A2784: Revision 2

- Rights: © The Boeing Company. Filed by the FAA in regulations.gov docket FAA-2016-5598; AD 2016-25-09 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication.
- Document: [Boeing Alert Service Bulletin 747-53A2784](https://openairdocs.org/service-documents/boeing/747-53a2784.md)
- Title as filed: U.S. DOT/FAA - Boeing SB-747-53A2784-02
- Pages: 248
- PDF: https://openairdocs.org/files/sha256/6a/61/6a6172e10cd12af1d650db07a3f544dd87c8be2de4eb50d4bc7e96adc2791c78
- Page: https://openairdocs.org/service-documents/boeing/747-53a2784/file/6a6172e10cd1

## Text

Some pages are OCR from a scan. OCR can misread letters and numbers. Each page's text from the PDF; open the PDF at a page with #page=N.

### Page 1

Commercial 
Airplanes
747
Service Bulletin
ALERT
Number: 747-53A2784
Original Issue: August 27, 2009
Revision 2: August 20, 2015
ATA System: 5310
SUBJECT: FUSELAGE - Main Frame - STA 320 Crown Frame - Web Inspection and Replacement
Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15
CFR 300-774). An export license may be required before it is used for development, production or use by foreign
persons from specific countries. The controller of this data has the individual responsibility to abide by all export
laws.
9E991ECCN:
BOEING PROPRIETARY, CONFIDENTIAL AND/OR TRADE SECRET
Copyright © 2009 Boeing.
Unpublished Work. All Rights Reserved.
Treatment of this document and its content is governed by contract with Boeing. Rights to use this document
are licensed on a per aircraft basis and such rights may not be transferable. For more information, contact The
Boeing Company.
Boeing, the Boeing signature, the Boeing symbol, 707, 717, 727, 737, 747, 757, 767, 777, 787, Dreamliner,
BBJ, DC-8, DC-9, DC-10, KC-10, KC-46, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8, Poseidon and
Boeing liveries are all trademarks owned by The Boeing Company; and no trademark license is granted in
connection with this document unless provided in writing by Boeing.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
1 of 248
5.0

### Page 2

Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
2 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT
BLANK PAGE

### Page 3

Table of Contents
Revision Transmittal Sheet ............................................ 5
S u m m a r y  ...................................................... 9
1. PLANNING INFORMATION ........................................ 1 3
A . E f f e c t i v i t y  ............................................... 1 3
1. Airplanes ............................................ 1 3
2 . S p a r e s  A f f e c t e d  ........................................ 1 5
B. Concurrent Requirements ...................................... 1 5
C. Reason ................................................ 1 6
D. Description .............................................. 1 7
E. Compliance .............................................. 1 8
F . A p p r o v a l  ............................................... 2 1
G. Manpower .............................................. 2 2
H. Weight and Balance Changes .................................... 2 3
I. Electrical Load Data ......................................... 2 3
J . R e f e r e n c e s  .............................................. 2 3
1. Existing Data: ......................................... 2 3
2. Data Supplied with this Service Bulletin: ........................... 2 4
3. Installation Drawings Used in the Preparation of this Service Bulletin: ........... 2 4
K. Publications Affected ........................................ 2 4
L. Interchangeability and Intermixability of Parts ........................... 2 5
M. Software Accomplishment Summary ................................ 2 5
2. MATERIAL INFORMATION ........................................ 2 7
A. Material - Price and Availability ................................... 2 7
B. Industry Support Information .................................... 2 7
C. Parts Necessary for Each Airplane ................................. 2 7
1 . K i t s / P a r t s  ............................................ 2 7
2. Parts and Materials Supplied by the Operator ........................ 3 8
3. Parts Modified and Reidentified ................................ 3 8
4. Parts Removed and Not Replaced .............................. 3 9
D. Parts Necessary to Change Spares ................................. 3 9
E. Special Tooling - Price and Availability ............................... 3 9
F. Special Tooling Necessary to do this Service Bulletin ....................... 3 9
3. ACCOMPLISHMENT INSTRUCTIONS .................................. 4 1
A. GENERAL INFORMATION ..................................... 4 1
B. WORK INSTRUCTIONS ....................................... 4 3
FIGURE 1: STA 300 TO STA 340 CROWN - ACCESS .......................... 4 8
FIGURE 2: STA 320 CROWN FRAME - WEB THICKNESS MEASUREMENT [Group 1, Configuration 1, 3]
.................................................. 5 1
FIGURE 3: STA 320 CROWN FRAME - INSPECTION [Group 1, Configuration 1, 3] .......... 5 3
F I G U R E  4 : D E L E T E D ............................................ 5 7
FIGURE 5: STA 320 CROWN FRAME - WEB INSPECTION [Group 1, Configuration 1, 3] ....... 5 8
FIGURE 6: STA 300 TO STA 340 CROWN - ACCESS PANEL REMOVAL ............... 6 3
FIGURE 7: STA 320 CROWN FRAME - STRAP, ANGLE, TEE, STIFFENER, CLIP AND BRACKET
R E M O V A L........................................... 6 9
FIGURE 8: STA 320 CROWN FRAME - LOWER CHORD REMOVAL .................. 8 7
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
3 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 4

FIGURE 9: STA 320 TO STA 340 CROWN - LEFT SIDE INTERCOSTAL REMOVAL ........ 1 0 0
FIGURE 10: STA 320 TO STA 340 CROWN - RIGHT SIDE INTERCOSTAL REMOVAL ........ 1 0 6
FIGURE 11: STA 320 CROWN FRAME - WEB REMOVAL ........................ 1 1 2
FIGURE 12: STA 320 CROWN FRAME - LOWER CHORD INSPECTION ............... 1 1 8
FIGURE 13: STA 320 CROWN FRAME - WEB INSTALLATION ..................... 1 2 3
FIGURE 14: STA 320 TO STA 340 CROWN - RIGHT SIDE INTERCOSTAL INSTALLATION ..... 1 3 1
FIGURE 15: STA 320 TO STA 340 CROWN - LEFT SIDE INTERCOSTAL INSTALLATION ...... 1 3 9
FIGURE 16: STA 320 CROWN FRAME - LOWER CHORD AND SPLICE INSTALLATION ...... 1 4 7
FIGURE 17: STA 320 CROWN FRAME - DRIPSHIELD BRACKET MODIFICATION OR FABRICATION . 161
FIGURE 18: STA 320 CROWN FRAME - STRAP, ANGLE, TEE STIFFENER, CLIP AND BRACKET
INSTALLATION ........................................ 1 6 4
FIGURE 19: STA 320 TO STA 340 CROWN - INTERCOSTAL, TEE AND STRAP INSTALLATION . . 191
FIGURE 20: STA 300 TO STA 340 CROWN - ACCESS PANEL INSTALLATION ........... 2 0 4
FIGURE 21: STA 300 TO STA 340 CROWN - CLOSE ACCESS ..................... 2 1 1
FIGURE 22: STA 300 TO STA 340 CROWN - ACCESS PANEL REMOVAL .............. 2 1 4
FIGURE 23: STA 320 CROWN FRAME - POST WEB REPLACEMENT INSPECTIONS ........ 2 2 0
FIGURE 24: STA 300 TO STA 340 CROWN - ACCESS PANEL INSTALLATION ........... 2 2 3
FIGURE 25: STA 320 CROWN FRAME - UPPER CHORD AND SKIN FASTENER REMOVAL .... 2 2 9
FIGURE 26: STA 320 CROWN FRAME - UPPER CHORD AND SKIN FASTENER INSTALLATION . 233
FIGURE 27: STA 320 CROWN FRAME - WEB WITH REPAIR DOUBLER - UPPER CHORD AND LOWER
CHORD INSPECTION [Group 1, Configuration 1, 3] .................... 2 3 8
FIGURE 28: STA 320 CROWN FRAME - FINISH APPLICATION .................... 2 4 1
APPENDIX A: 015U1848-1 TOP KIT - PARTS LIST AND FIGURE KITS ................. 2 4 3
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
4 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 5

Commercial 
Airplanes
747
Service Bulletin
ALERT
Revision Transmittal SheetNumber: 747-53A2784Original Issue: August 27, 2009
Revision 2: August 20, 2015
ATA System: 5310
SUBJECT: FUSELAGE - Main Frame - STA 320 Crown Frame - Web Inspection and Replacement
This revision includes all pages of the service bulletin.
COMPLIANCE INFORMATION RELATED TO THIS REVISION
Federal Aviation Administration (FAA) Airworthiness Directive (AD) AD 2012-22-02 is related to this service
bulletin.
Effects of this Revision on airplanes on which the Original Issue or Revision 1 was previously done:
ActionConditionGroup
No further action required.Web thickness is greater than 0.145
inch.
Group 1, Configuration 2
Do web replacement at the time
given in Paragraph 1.E., Compli-
ance.
Web thickness is less than 0.078
inch, or greater than or equal to
0.084 inch and less than or equal to
0.135 inch.
Group 1, Configuration 2
REASON FOR REVISION
This revision is sent to include a greater range of thicknesses of the Body Station (STA) 320 crown frame web
for which work is required in accordance with this service bulletin. In previous issues of this bulletin, there was
no work included for airplanes with a STA 320 crown frame web thickness less than 0.078 inch or between
0.084 and 0.135 inch. Since the release of Revision 1 of this service bulletin, Operators have reported that their
airplanes had STA 320 crown frame web thicknesses that did not fall within the ranges given in Revision 1 of
this service bulletin.
These sections were changed:
1. In Background, in the Summary section, the Summary Evaluation Table and a second Boeing Service
Related Problem (SRP) were added.
2. In Action, in the Summary section, revised to include revised work and match the Description section.
3. In Compliance, in the Summary section, included a reference to the AD associated with this service
bulletin.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
5 of 248

### Page 6

4. In Manpower, in the Summary section, task hours and elapsed hours changed.
5. The Summary Illustration, in the Summary section, the range of STA 320 crown frame web thicknesses
and applicable work updated.
6. In Paragraph 1.A.1., Effectivity, added the D6 document paragraph and the effectivity divided into
configurations.
7. In Paragraph 1.C., Reason, paragraph added to explain the reason for the revised work in Revision 2.
8. In Paragraph 1.D., Description, the range of STA 320 crown frame web thicknesses and applicable
work updated.
9. In Paragraph 1.E., Compliance, included a reference to the AD associated with this service bulletin.
Added statement to refer to Accomplishment Instructions for required actions. The range of STA 320
crown frame web thicknesses and applicable work is updated in Table 1, Table 2 and Table 3. Added
new Table 5 for airplanes with STA 320 crown frame web thicknesses that did not fall within the ranges
given in the Original Issue or Revision 1.
10. In Paragraph 1.F., Approval, added AMOC statement.
11. In Paragraph 1.G., Manpower, added new task figures.
12. In Paragraph 1.J.1., Existing Data, added a reference to the AD associated with this service bulletin
and references to Boeing Service Letters, FAA ADs and Aircraft Maintenance Manuals.
13. In Paragraph 1.K., Publications Affected, added Illustrated Parts Catalog reference.
14. In Paragraph 1.M., Software Accomplishment Summary revised.
15. In Paragraph 2.C.1, Kits/Parts, added a note to clarify a countersunk washer.
16. In Paragraph 2.C.2, Parts and Materials Supplied by the Operator, added two optional parts.
17. In Paragraph 3.B., Work Instructions, revised the general notes in accordance with new requirements.
18. In Paragraph 3.B., Work Instructions, added a range of STA 320 crown frame web thicknesses and
applicable work.
19. Figure 8, increased the maximum allowed cut width on the lower chord.
20. Figure 13, added note for replacing missing fasteners.
21. Figures 14 through 16, 18, and 19, added optional nut and washer for the existing collar.
22. Figure 16 and 18 removed the requirement to install fasteners on the near side.
23. In Figure 18 and 19, revised the fastener code tables to clarify a countersunk washer.
24. In Figure 18, sheets 12 and 13, revised fastener codes to specify the direction of installation.
25. Figure 19, revised sheet 2, 3, and 4, to incorporate step number changes.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
6 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 7

26. Figure 27, added figure to show inspection areas specific to STA 320 crown frame webs with repair
doubler installed.
27. Figure 28, added figure for paint application.
28. In Appendix A, revised to clarify a countersunk washer.
The data given in Alternative Method of Compliance Notice 747-53A2784 AMOC 01 is included in this revision.
Vertical lines are put on the left edge of each page, except in Paragraph 1.A., Effectivity and format changes,
to show the location of all content changes.
Pages with no vertical lines have no changes.
REVISION HISTORY
August 27, 2009Original Issue:
September 14, 2011Revision 1:
August 20, 2015Revision 2:
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
7 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 8

Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
8 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT
BLANK PAGE

### Page 9

Commercial 
Airplanes
747
Service Bulletin
ALERT
SummaryNumber: 747-53A2784Original Issue: August 27, 2009
Revision 2: August 20, 2015
ATA System: 5310
SUBJECT: FUSELAGE - Main Frame - STA 320 Crown Frame - Web Inspection and Replacement
THIS BULLETIN IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN PARAGRAPH
1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS SERVICE BULLETIN TO
THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE BULLETIN TO
THE NEW OWNER.
CONCURRENT REQUIREMENTS
None.
BACKGROUND
Boeing has determined that the web of the STA 320 crown frame on some 747-400 airplanes may not be the
correct design thickness and the frame assembly could be missing fasteners. If the web is not the correct
thickness or if the frame assembly is missing fasteners, cracks could exist. If crown frame cracks exist and are
not found, the cracks could grow and lead to complete fracture of the STA 320 crown frame assembly. Complete
fracture of the crown frame assembly may result in damage to the skin and in-flight decompression of the
airplane.
During production an error was made on early 747-400's affecting the thickness of the STA 320 crown frame
web, which is located between Left Buttock Line (LBL) 25 and Right Buttock Line (RBL) 25, Water Line (WL)
380. Records indicate that the drawing was revised in September 1988 to increase the STA 320 crown frame
web thickness to 0.14 inch for 747-400 airplanes, however this change was not implemented in production until
September 1992. The result of this error was the continued installation of a 0.08 inch thick web instead of a 0.14
inch thick STA 320 crown frame web. If the 0.08 inch thick web is not replaced it could crack due to fatigue.
Boeing has also had a report of missing fasteners common to the web.
Initially, two operators informed Boeing of a crown frame web crack at LBL 15.0, STA 320. The cracks were
both 0.65 inches in length and were reported after 9,354 flight cycles on one airplane and 12,851 flight cycles
on the other airplane. Further investigation revealed that in both cases the web was made from 0.08 inch thick
material and did not conform to production drawings. Also, an operator has reported missing fasteners from
locations common to the frame web and lower chord on the first delivered 747-400 after 10,317 flight cycles.
This airplane also had a web made from 0.08 inch thick material and did not conform to production drawings.
Since the Original Issue of this service bulletin, Boeing has received three more reports of STA 320 crown frame
web cracking on 747-400 airplanes with a 0.08 inch thick web. The reports were of a crack (length not specified)
reported at 9,456 flight cycles, a 0.65 inch crack reported at 29,866 flight cycles and a 0.85 inch crack reported
at 29,956 flight cycles.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
9 of 248

### Page 10

Accomplishment of the work given in this service bulletin will determine if the web of the STA 320 crown frame
is the correct design thickness and if fasteners are missing from the web. If the web is not the correct thickness,
or is missing fasteners, this service bulletin provides inspections to find possible cracks in the STA 320 crown
frame. This service bulletin also provides instructions for replacement of the STA 320 crown frame web if it is
not the correct design thickness.
747-SRP-53-0319 and 747-SRP-53-0480 are related to this service bulletin.
As a part of a service bulletin validation program, this inspection and change was completed on airplane RT437
by Service Bulletin 747-53A2784 Original Issue before the release of Revision 1 of this service bulletin. The
inspection and change completed on airplane RT437 by Service Bulletin 747-53A2784 Original Issue is equivalent
to the release of Revision 1 of this service bulletin. Airplane RT437 has the configuration of a Group 1 airplane.
This table is provided to operators for planning purposes only. Refer to the applicable sections for more
information.
ReferenceAffectedPlanning Data
Paragraph 1.A.2., Spares AffectedNoSpares Affected
Paragraph 1.E., Compliance and Paragraph
1.F., Approval
YesAD Related
Paragraph 1.H., Weight and Balance ChangesYesWeight and Balance Change
Paragraph 1.I., Electrical Load DataNoElectrical Load Changed
Paragraph 1.K., Publications AffectedYesPublications Affected
Paragraph 1.K., Publications AffectedNoAirplane Flight Operations Affected (Flight Crew
Operations Manual and/or FAA Approved Air-
plane Flight Manual)
Paragraph 2.C.1., Kits/PartsYesKits/Parts Required
Paragraph 2.C.2., Parts and Materials Supplied
by the Operator
YesOperator Supplied Parts/Material
Paragraph 2.F., Special Tooling Necessary to
do this Service Bulletin
NoSpecial Tooling Required
ACTION (PRR 85901-93RS)
Group 1, Configuration 1:
Airplanes that have been inspected in accordance with the Original Issue or Revision 1 of this service bulletin,
have a web of thickness greater than or equal to 0.078 inch and less than or equal to 0.083 inch, which remains
installed: do web replacement. For airplanes with a replaced web: do repetitive detailed inspections of the web,
upper chord, lower chord and lower chord splice for any crack. If any crack is found, contact The Boeing Company
for repair instructions and do the repair. Airplanes with an original 0.136-0.145 inch thick web: no further action
is required.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
10 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 11

Group 1, Configuration 2:
Airplanes that have had the web thickness measured in accordance with the Original Issue or Revision 1 of this
service bulletin, have a web thickness less than 0.078 inch, or greater than or equal to 0.084 inch and less than
or equal to 0.135 inch, which remains installed: do web replacement. After the web is replaced, do repetitive
detailed inspections of the web, upper chord, lower chord and lower chord splice for any crack. If any crack is
found, contact The Boeing Company for repair instructions and do the repair. Airplanes with an original web
with thickness greater than 0.145 inch: no further action is required.
Group 1, Configuration 3:
Measure the thickness of the STA 320 crown frame web. Airplanes that have not had the inspection done in
accordance with the Original Issue or Revision 1 of this service bulletin with a web thickness less than 0.136
inch and no repair doubler installed on the web: do a detailed inspection for any crack and a general visual
inspection for missing fasteners of the STA 320 crown frame from LBL 30.0 to RBL 30.0. If any crack is found
in the web, do web replacement. If any crack is found in the upper chord or lower chord, contact The Boeing
Company for repair instructions and do the repair. If no crack is found in the web, do web replacement, or, do
a High Frequency Eddy Current (HFEC) inspection of the web, and if no crack is found, the web can be replaced
at a later time. Install any missing fasteners. After a web is replaced, do repetitive detailed inspections of the
web, upper chord, lower chord, and lower chord splice for any crack. If any crack is found, contact The Boeing
Company for repair instructions and do the repair. Airplanes that have not had the inspection done in accordance
with the Original Issue or Revision 1 of this service bulletin with a web thickness less than 0.136 inch and a
repair doubler installed on the web: do a detailed inspection for any crack in the upper chord and lower chord
and a general visual inspection for missing fasteners of the STA 320 crown frame from LBL 30.0 to RBL 30.0.
If any crack is found in the upper chord or lower chord, contact The Boeing Company for repair instructions and
do the repair. Install any missing fasteners. Replace the web. After a web is replaced: do repetitive detailed
inspections of the web, upper chord, lower chord, and lower chord splice for any crack. If any crack is found,
contact The Boeing Company for repair instructions and do the repair. Airplanes with a web thickness greater
than or equal to 0.136 inch: no further action is required.
EFFECTIVITY
747-400/-400D/-400F airplanes. Refer to Paragraph 1.A.1., Airplanes for the list of affected airplanes.
COMPLIANCE
Federal Aviation Administration (FAA) Airworthiness Directive AD 2012-22-02 is related to this service bulletin.
The effective date of AD 2012-22-02 is December 26, 2012.
Refer to Paragraph 1.E., Compliance.
INDUSTRY SUPPORT INFORMATION
Boeing warranty remedies are not available for the inspection and/or repair procedures given in this service
bulletin.
MANPOWER
Elapsed HoursTotal Task HoursAirplanes
128.85218.85All airplanes
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
11 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 12 (OCR)

BOEING SERVICE BULLETIN 747-53A2784
ALERT  ALERT
MATERIAL INFORMATION
Boeing Supplied Kits/Parts.
Refer to Paragraph 2.A., Material - Price and Availability.
MEASURE THE THICKNESS OF THE STA 320
CROWN FRAME WEB. IF WEB THICKNESS
IS 0.136 INCH OR GREATER, NO FURTHER
ACTION IS REQUIRED.
DO POST STA 320
CROWN FRAME WEB  RBL
REPLACEMENT  INSPECTION  7.5
BL
LBL
7.5
IF WEB THICKNESS IS
LESS THAN 0.136 INCH,
INSTALL A NEW FRAME
WEB. INSTALL ANY
MISSING FASTENERS
STA
320
IF ANY CRACK IS FOUND IN THE UPPER
CHORD OR LOWER CHORD, CONTACT THE
BOEING COMPANY FOR REPAIR
INSTRUCTIONS AND DO THE REPAIR.
ALBL
15.0
SOME STRUCTURE NOT SHOWN FOR CLARITY  1703583
Original Issue: August 27, 2009
Revision 2: August 20, 2015  PROPRIETARY - Copyright © Unpublished  Export Controlled ECCN: 9E991 - BOEING  747-53A2784
Work - See page 1 for details.  12 of 248

### Page 13

Commercial 
Airplanes
747
Service Bulletin
ALERT
Number: 747-53A2784
Original Issue: August 27, 2009
Revision 2: August 20, 2015
ATA System: 5310
SUBJECT: FUSELAGE - Main Frame - STA 320 Crown Frame - Web Inspection and Replacement
THIS BULLETIN IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN PARAGRAPH
1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS SERVICE BULLETIN TO
THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE BULLETIN TO
THE NEW OWNER.
1.    PLANNING INFORMATION
A. Effectivity
1. Airplanes
This service bulletin is applicable to 747-400 Airplanes, line numbers 696-991 in 1 Group. The
Variable Numbers and Group Information for the applicable airplanes is given below.
Refer to Service Bulletin Index D6-30300 Part 3 for Airplane Variable Number, Line Number, and
Serial Number data.
This service bulletin is for the airplanes shown below. An equivalent change is on subsequent
production airplanes. Refer to PRR85901-93RS for data about this change.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
13 of 248

### Page 14

DESCRIPTIONCONFIGURATIONGROUP
747-400, -400D, and -400F airplanes, line numbers 696 through 991.-1
Airplanes that have been inspected in accordance with the Original
Issue or Revision 1 of this service bulletin where the measured web
thickness was addressed in the Original Issue or Revision 1 of this
service bulletin. The thickness was greater than or equal to 0.078
inch and less than or equal to 0.083 inch, or greater than or equal to
0.136 inch and less than or equal to 0.145 inch.
1
Airplanes that have been inspected in accordance with the Original
Issue or Revision 1 of this service bulletin where the measured web
thickness was not addressed in the Original Issue or Revision 1 of
this service bulletin. The thickness was less than 0.078 inch, or
greater than or equal to 0.084 inch and less than or equal to 0.135
inch, or greater than 0.145 inch.
2
Airplanes that have not been inspected in accordance with the original
issue or Revision 1 of this service bulletin.
3
Airplane Models:
747-400, 747-400D, 747-400F
GroupVariable Number
1RR701
1RT001 - RT009
1RT021 - RT022
1RT031 - RT033
1RT041 - RT047
1RT061
1RT071 - RT075
1RT101 - RT103
1RT121
1RT131 - RT133
1RT401 - RT412
1RT431 - RT441
1RT451 - RT465
1RT471 - RT496
1RT501 - RT520
1RT531 - RT535
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
14 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 15

GroupVariable Number
1RT551 - RT568
1RT571 - RT581
1RT591
1RT601 - RT622
1RT631 - RT635
1RT641 - RT657
1RT671 - RT673
1RT681 - RT682
1RT691 - RT696
1RT701 - RT704
1RT711 - RT717
1RT741 - RT745
1RT751 - RT755
1RT776 - RT777
1RT781 - RT783
1RT861 - RT864
1RT876 - RT878
1RT931 - RT932
1RT951 - RT954
1RU001
1RU031
1RU801 - RU808
1RU831 - RU838
2. Spares Affected
None.
B. Concurrent Requirements
None.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
15 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 16

C. Reason
Boeing has determined that the web of the Body Station (STA) 320 crown frame on some 747-400
airplanes may not be the correct design thickness and the frame assembly could be missing fasteners.
If the web is not the correct thickness or if the frame assembly is missing fasteners, cracks could exist.
If crown frame cracks exist and are not found, the cracks could grow and lead to complete fracture of
the STA 320 crown frame assembly. Complete fracture of the crown frame assembly may result in
damage to the skin and in-flight decompression of the airplane.
During production an error was made on early 747-400's affecting the thickness of the STA 320 crown
frame web, which is located between Left Buttock Line (LBL) 25 and Right Buttock Line (RBL) 25,
Water Line (WL) 380. Records indicate that the drawing was revised in September 1988 to increase
the STA 320 crown frame web thickness to 0.14 inch for 747-400 airplanes, however this change was
not implemented in production until September 1992. The result of this error was the continued
installation of a 0.08 inch thick web instead of a 0.14 inch thick web. If the 0.08 inch thick web is not
replaced it could crack due to fatigue. Boeing has also had a report of missing fasteners common to
the web.
Initially, two operators informed Boeing of a crown frame web crack at LBL 15.0, STA 320. The cracks
were both 0.65 inches in length and were reported after 9,354 flight cycles on one airplane and 12,851
flight cycles on the other airplane. Further investigation revealed that in both cases the web was made
from 0.08 inch thick material and did not conform to production drawings. Also, an operator has reported
missing fasteners from locations common to the frame web and lower chord on the first delivered
747-400 after 10,317 flight cycles. This airplane also had a web made from 0.08 inch thick material
and did not conform to production drawings.
Since the Original Issue of this service bulletin, Boeing has received three more reports of STA 320
crown frame web cracking on 747-400 airplanes with a 0.08 inch thick web. The reports were of a crack
(length not specified) reported at 9,456 flight cycles, a 0.65 inch crack reported at 29,866 flight cycles
and a 0.85 inch crack reported at 29,956 flight cycles.
Accomplishment of the work given in this service bulletin will determine if the web of the STA 320 crown
frame is the correct design thickness and if fasteners are missing from the web. If the web is not the
correct thickness, or is missing fasteners, this service bulletin provides inspections to find possible
cracks in the STA 320 crown frame. This service bulletin also provides instructions for replacement of
STA 320 crown frame web if it is not the correct design thickness.
747-SRP-53-0319 and 747-SRP-53-0480 are related to this service bulletin.
As a part of a service bulletin validation program, this inspection and change was completed on airplane
RT437 by Service Bulletin 747-53A2784 Original Issue before the release of Revision 1 of this service
bulletin. The inspection and change completed on airplane RT437 by Service Bulletin 747-53A2784
Original Issue is equivalent to the release of Revision 1 of this service bulletin. Airplane RT437 has the
configuration of a Group 1 airplane.
Revision 2 is sent to include a greater range of thicknesses of the STA 320 crown frame web for which
work is required in accordance with this service bulletin. In previous issues of this bulletin, there was
no work included for airplanes with a STA 320 crown frame web thickness less than 0.078 inch, or
greater than or equal to 0.084 and less than or equal to 0.135 inch. Since the release of Revision 1 of
this service bulletin, Operators have reported that their airplanes had STA 320 crown frame web
thicknesses that did not fall within the ranges given in Revision 1 of this service bulletin.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
16 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 17

D. Description
Group 1, Configuration 1:
Airplanes that have been inspected in accordance with the Original Issue or Revision 1 of this service
bulletin, have a web of thickness greater than or equal to 0.078 inch and less than or equal to 0.083
inch, which remains installed: do web replacement. For airplanes with a replaced web: do repetitive
detailed inspections of the web, upper chord, lower chord and lower chord splice for any crack. If any
crack is found, contact The Boeing Company for repair instructions and do the repair. Airplanes with
an original 0.136-0.145 inch thick web: no further action is required.
Group 1, Configuration 2:
Airplanes that have had the web thickness measured in accordance with the Original Issue or Revision
1 of this service bulletin, have a web thickness less than 0.078 inch, or greater than or equal to 0.084
inch and less than or equal to 0.135 inch, which remains installed: do web replacement. After the web
is replaced, do repetitive detailed inspections of the web, upper chord, lower chord and lower chord
splice for any crack. If any crack is found, contact The Boeing Company for repair instructions and do
the repair. Airplanes with an original web with thickness greater than 0.145 inch: no further action is
required.
Group 1, Configuration 3:
Measure the thickness of the STA 320 crown frame web. Airplanes that have not had the inspection
done in accordance with the Original Issue or Revision 1 of this service bulletin with a web thickness
less than 0.136 inch and no repair doubler installed on the web: do a detailed inspection for any crack
and a general visual inspection for missing fasteners of the STA 320 crown frame from LBL 30.0 to
RBL 30.0. If any crack is found in the web, do web replacement. If any crack is found in the upper chord
or lower chord, contact The Boeing Company for repair instructions and do the repair. If no crack is
found in the web, do web replacement, or, do a High Frequency Eddy Current (HFEC) inspection of
the web, and if no crack is found, the web can be replaced at a later time. Install any missing fasteners.
After a web is replaced, do repetitive detailed inspections of the web, upper chord, lower chord, and
lower chord splice for any crack. If any crack is found, contact The Boeing Company for repair instructions
and do the repair. Airplanes that have not had the inspection done in accordance with the Original
Issue or Revision 1 of this service bulletin with a web thickness less than 0.136 inch and a repair doubler
installed on the web: do a detailed inspection for any crack in the upper chord and lower chord and a
general visual inspection for missing fasteners of the STA 320 crown frame from LBL 30.0 to RBL 30.0.
If any crack is found in the upper chord or lower chord, contact The Boeing Company for repair
instructions and do the repair. Install any missing fasteners. Replace the web. After a web is replaced:
do repetitive detailed inspections of the web, upper chord, lower chord, and lower chord splice for any
crack. If any crack is found, contact The Boeing Company for repair instructions and do the repair.
Airplanes with a web thickness greater than or equal to 0.136 inch: no further action is required.
Effects of this Revision on airplanes on which the Original Issue or Revision 1 was previously done:
ActionConditionGroup
No further action required.Web thickness is greater than 0.145
inch.
Group 1, Configuration 2
Do web replacement at the time
given in Paragraph 1.E., Compli-
ance.
Web thickness is less than 0.078
inch, or greater than or equal to
0.084 inch and less than or equal to
0.135 inch.
Group 1, Configuration 2
The work in this service bulletin is done in the maintenance zone(s) given below.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
17 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 18

Affected Maintenance Zones
ZoneModel
221, 222747-400, 747-400D, 747-400F
E. Compliance
Federal Aviation Administration (FAA) AD 2012-22-02 is related to this service bulletin. The effective
date of AD 2012-22-02 is December 26, 2012.
Do the required actions in accordance with Paragraph 3. Accomplishment Instructions.
Group 1, Configuration 3:
Table 1: STA 320 Crown Frame Web Thickness Measurement
Compliance Time
(Whichever Occurs Later)
ActionCondition
Within 2,200
flight cycles after
the effective date
of AD 2012-22-
02.
Before
4,000 total
flight cy-
cles.
Measure the thickness of the web in
accordance with paragraph 3.B.
WORK INSTRUCTIONS, PART 2.
All airplanes
-No further action is required.All airplanes with a web thickness of
0.136 inch or greater.
In accordance with Table 2.Do the work in accordance with Table
2.
All airplanes with a web thickness less
than 0.136 inch and no repair doubler
installed on the web.
In accordance with Table 3.Do the work in accordance with Table
3.
All airplanes with a web thickness less
than 0.136 inch and a repair doubler
installed on the web.
Group 1, Configuration 1, 3:
Table 2: STA 320 Crown Frame Inspection and Web Replacement (Web with No Repair Doubler)
Compliance Time
(Whichever Occurs Later)
ActionCondition
Within 2,200
flight cycles after
the effective date
of AD 2012-22-
02.
Before
4,000 total
flight cy-
cles.
Do a detailed inspection for any crack
and a general visual inspection for
missing fasteners in the STA 320
crown frame in accordance with para-
graph 3.B. WORK INSTRUCTIONS,
PART 3, step 1.
All airplanes with a web thickness less
than 0.136 inch and no repair doubler
installed on the web.
Before further flight.Contact The Boeing Company for re-
pair instructions and do the repair.
Any crack is found in the upper or
lower chord.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
18 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 19

Group 1, Configuration 1, 3:
Table 2: STA 320 Crown Frame Inspection and Web Replacement (Web with No Repair Doubler)
Compliance Time
(Whichever Occurs Later)
ActionCondition
Before further flight.Replace the web in accordance with
paragraph 3.B. WORK INSTRUC-
TIONS, PART 5. (a)
Any crack is found in the web.
Before further flight.OPTION 1: Replace the web in accor-
dance with paragraph 3.B. WORK IN-
STRUCTIONS, PART 5 (a)
No crack is found in the web.
OR
OPTION 2: Do a HFEC inspection for
cracks around the holes in the web in
accordance with paragraph 3.B.
WORK INSTRUCTIONS, PART 3, step
1. c.(2)
Before further flight.Replace the web in accordance with
paragraph 3.B. WORK INSTRUC-
TIONS, PART 5 (a)
Option 2 HFEC inspection is accom-
plished and any crack is found in the
web.
Within 3,000 flight cycles after
accomplishment of the HFEC
inspection.
Replace the web in accordance with
paragraph 3.B. WORK INSTRUC-
TIONS, PART 5 (a)
Option 2 HFEC inspection is accom-
plished and no crack is found in the
web.
Before further flight.Replace missing fasteners in accor-
dance with paragraph 3.B. WORK IN-
STRUCTIONS, PART 3, step
1.c.(2)(b)1)
If any missing fasteners are found.
(a) After web replacement, do the post web replacement inspections in accordance with Table 4.
Group 1, Configuration 1, 3:
Table 3: STA 320 Crown Frame Inspection and Web Replacement (Web with Repair Doubler)
Compliance Time
(Whichever Occurs Later)
ActionCondition
Within 2,200
flight cycles after
the effective date
of AD 2012-22-
02.
Before
4,000 total
flight cy-
cles.
Do a detailed inspection for any crack
in the upper chord and lower chord of
the STA 320 crown frame in accor-
dance with paragraph 3.B. WORK IN-
STRUCTIONS, PART 4, step 1.
All airplanes with a web thickness less
than 0.136 inch and a repair doubler
installed on the web.
Before further flight.Replace the web in accordance with
paragraph 3.B. WORK INSTRUC-
TIONS, PART 5. (a)
No crack found.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
19 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 20

Group 1, Configuration 1, 3:
Table 3: STA 320 Crown Frame Inspection and Web Replacement (Web with Repair Doubler)
Compliance Time
(Whichever Occurs Later)
ActionCondition
Before further flight.Contact The Boeing Company for re-
pair instructions and do the repair
Any crack is found in the upper or
lower chord.
AND
Replace the web in accordance with
paragraph 3.B. WORK INSTRUC-
TIONS, PART 5. (a)
(a) After web replacement, do the post web replacement inspections in accordance with Table 4.
Table 4: STA 320 Post Web Replacement Inspections
Repeat Interval
(Not to Exceed)
Compliance
Time
ActionCondition
(a)Within 15,000
flight cycles after
web replace-
ment.
Do a detailed inspection of the
web, upper chord, lower chord
and lower chord splice for any
crack in accordance with para-
graph 3.B. WORK INSTRUC-
TIONS, PART 7, step 4.
All airplanes that have done the
STA 320 crown frame web re-
placement in accordance with
paragraph 3.B. WORK INSTRUC-
TIONS, PART 5
3,000 flight cycles.
(a)
-Repeat the detailed inspection of
the web, upper chord, lower
chord, and lower chord splice for
any crack in accordance with
paragraph 3.B. WORK INSTRUC-
TIONS, PART 7, step 4.
No crack found.
-Before further
flight.
Contact The Boeing Company for
repair instructions and do the re-
pair.
Any crack found.
(a) When inspections in accordance with FAA AD 2009-19-05 start, the STA 320 Post Web Replacement
Inspections are not required. FAA AD 2009-19-05 is related to Boeing Service Bulletin 747-53A2753.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
20 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 21

Group 1, Configuration 2:
Table 5: STA 320 Crown Frame Inspection and Web Replacement (More Work Required)
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
-Within 2,200 flight cycles after the
Revision 2 date of this service
bulletin.
Replace the web in accor-
dance with paragraph
3.B. WORK INSTRUC-
TIONS, PART 8, step 2.
(a)
All airplanes with web
thickness measured in ac-
cordance with the Original
Issue or Revision 1 of this
service bulletin. The web is
less than 0.078 inch, or
greater than or equal to
0.084 inch and less than or
equal to 0.135 inch. The
original web remains in-
stalled and was not inspect-
ed for any crack.
-Within 2,200
flight cycles af-
ter the Revision
2 date of this
service bulletin.
Within 3,000
flight cycles af-
ter accomplish-
ment of the
HFEC inspec-
tion.
Replace the web in accor-
dance with paragraph
3.B. WORK INSTRUC-
TIONS, PART 8, step 2.
(a)
All airplanes with web
thickness measured in ac-
cordance with the Original
Issue or Revision 1 of this
service bulletin. The web is
less than 0.078 inch, or
greater than or equal to
0.084 inch and less than or
equal to 0.135 inch. The
original web remains in-
stalled, it was inspected for
any crack and no crack
was found.
--No further action re-
quired.
All airplanes with original
web thickness greater than
0.145 inch.
(a) After web replacement, do the post web replacement inspections in accordance with Table 4.
F. Approval
This service bulletin was examined by the Federal Aviation Administration (FAA). The changes specified
in this service bulletin comply with the applicable regulations and are FAA approved, as well as European
Aviation Safety Agency (EASA)/Joint Aviation Authorities (JAA) approved for all EASA/JAA approved
airplanes listed in the service bulletin effectivity. This service bulletin and its approval were based on
the airplane in its original Boeing delivery configuration or as modified by other approved Boeing
changes.
If an airplane has a non-Boeing modification or repair that affects a component or system also affected
by this service bulletin, the operator is responsible for obtaining appropriate regulatory agency approval
before incorporating this service bulletin.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
21 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 22

In addition, the Manager of the FAA Seattle Aircraft Certification Office also approves the accomplishment
of the inspection and STA 320 crown frame web replacement with the corresponding compliance times
given in Service Bulletin 747-53A2784, Revision 2, as an alternative method of compliance (AMOC)
to the corresponding inspection and STA 320 crown frame web replacement requirements of paragraphs
(h), (i), and (j) of AD 2012-22-02. This AMOC applies only to the areas inspected in accordance with
this service bulletin. All other inspections outside of this service bulletin inspection region are not affected
and must continue. Where this service bulletin instructs to contact The Boeing Company for repair
instructions, the repair instructions must be approved by the FAA in accordance with paragraph (m) of
the AD. All provisions of AD 2012-22-02 that are not specifically referenced in this paragraph, remain
fully applicable and must be complied with accordingly.
G. Manpower
The table below shows an estimate of the task hours necessary to do this service bulletin for each
airplane. This estimate is for direct labor only, done by an experienced crew. Adjust the estimate with
operator task hour data if necessary. The estimate does not include lost time. These are some examples
of lost time:
• Time to adjust to the workplace
• Time to schedule the work
• Time to inspect the work
• Time to cure the materials
• Time to make the parts
• Time to find the tools.
Elapsed HoursTask HoursNumber of Per-
sons
Task
25.5051.002FIGURE 1
0.100.101FIGURE 2
3.003.001FIGURE 3
3.003.001FIGURE 5
2.502.501FIGURE 6
4.258.502FIGURE 7
2.755.502FIGURE 8
3.753.751FIGURE 9
3.753.751FIGURE 10
1.501.501FIGURE 11
2.755.502FIGURE 12
2.002.001FIGURE 13
3.753.751FIGURE 14
3.753.751FIGURE 15
3.256.502FIGURE 16
1.001.001FIGURE 17
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
22 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 23

Elapsed HoursTask HoursNumber of Per-
sons
Task
6.5013.002FIGURE 18
4.509.002FIGURE 19
2.502.501FIGURE 20
37.5075.002FIGURE 21
1.503.002FIGURE 22
2.502.501FIGURE 23
1.503.002FIGURE 24
2.002.001FIGURE 25
1.051.051FIGURE 26
1.201.201FIGURE 27
1.501.501FIGURE 28
128.85218.85TOTAL FOR EACH AIRPLANE
H. Weight and Balance Changes
Change in Moment
(Pound-Inches)
Change in Weight
(Pounds)Airplane
+1792.0+5.6All airplanes - Web
replacement
I. Electrical Load Data
Not changed.
J. References
1. Existing Data:
a. Engineering Change Memo PRR 85901-93RS
b. Boeing Parts Standards Document D-590
c. Boeing Service Bulletin 747-53A2753
d. Boeing Service Letter 747-SL-00-018, 747-SL-51-048
e. Boeing Service Related Problem (SRP) 747-SRP-53-0319, 747-SRP-53-0480
f. Federal Aviation Administration (FAA) Airworthiness Directive (AD) 2009-19-05, 2012-22-02
g. Service Bulletin Index D6-30300
h. Standard Overhaul Practices Manual (SOPM) 20-41-02, 20-43-03, 20-50-10, 20-50-19
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
23 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 24

i. Standard Wiring Practices Manual (SWPM) 20-10-11, 20-10-12, 20-10-19
j. 747 Non-Destructive Testing (NDT) Manual PART 6, 51-00-00
k. 747-400 Aircraft Maintenance Manual (AMM), 25-11-01, 25-14-00, 25-14-01, 25-15-00,
25-21-00, 25-22-00, 31-00-00, 51-21-01
l. 747-400 Structural Repair Manual (SRM) 51-40-05, 51-40-06
m. 747-400F Structural Repair Manual (SRM) 51-40-05, 51-40-06
n. 747-400SF Structural Repair Manual (SRM) 51-40-05, 51-40-06
2. Data Supplied with this Service Bulletin:
None.
3. Installation Drawings Used in the Preparation of this Service Bulletin:
TitleDrawing Number
SKIN & DOUBLER INSTL - UPPER CROWN CAB141U8009
DUCT INSTL - AIR CONDITIONING, FLIGHT DECK214U1002
DRIPSHIELD INSTL - OVERHEAD PILOTS (POH)232U1301
FRAME INSTALLATION - UPPER CROWN, CAB STATION 32065B07603
NO. 2 POST INSTL - WINDSHIELD LINE C-D65B07612
INTERCOSTAL INSTL - BL"0", UPPER CROWN, STA 290-36065B07614
SILL INSTL - UPPER, UPPER CROWN, CAB, SECTION 4165B07616
INTERCOSTAL INSTL - UPPER CROWN, CAB, BL 7.50 & BL
15.00
65B07617
FRAME INSTL - STA 340, BODY CAB65B10334
These drawings were used to prepare this service bulletin. These drawings are not necessary to
make the specified changes, and are not supplied with this service bulletin. These drawings may
not be applicable to all airplane configurations or operators.
K. Publications Affected
1. Publications:
Chapter-SectionPublication
53-10747 Structural Repair Manual
53-10747 Illustrated Parts Catalog
2. Damage Tolerance Based Structural Inspections:
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
24 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 25

Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue
Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the
Maintenance Program. This service bulletin affects FCS and new DTI requirements for the structure
affected are contained in Paragraph 1.E., Compliance of this service bulletin.
L. Interchangeability and Intermixability of Parts
Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts.
M. Software Accomplishment Summary
Not affected.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
25 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 26

Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
26 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT
BLANK PAGE

### Page 27

2.    MATERIAL INFORMATION
A. Material - Price and Availability
Boeing can supply the kits shown in Paragraph 2.C., Parts Necessary for Each Airplane. Operators
are encouraged to share schedule requirements with Boeing for incorporation of the service bulletin.
The kits are subject to the terms and conditions of the Boeing standard purchase order acknowledgment.
Prices are in United States Dollars. Terms: Net 30 days.
Reference this service bulletin and submit your purchase order by one of these methods:
1. Order on-line via ATA Spec 2000 or The Boeing PART Page
2. Fax to (206) 662-7145
REFER TO THE BOEING PART PAGE ON MYBOEINGFLEET.COM OR CONTACT FIRST RESPONDER
AT FR@BOEING.COM FOR THE LATEST REORDER LEAD TIME (ROLT) AND PRICE INFORMATION
Unit Price as of
the Revision 01
date of this Ser-
vice Bulletin
(US Dollars)
ROLT as of the
Revision 01 date
of this Service
Bulletin
(Calendar Days)
QTYDateNameKit Number
(a)(a)(a)(a)TOP KIT - FRAME
WEB REPLACEMENT,
STA 320 CROWN
015U1848-1
21,887.005101011/11/11TOP KIT - FRAME
WEB REPLACEMENT,
STA 320 CROWN
015U1848-2
105.00390--SUPPLEMENTAL KIT
- FRAME WEB RE-
PLACEMENT, STA 320
CROWN
015U1848-3
(a) A limited quantity of 015U1848-1 top kits will be available until the 015U1848-2 top kit becomes available.
Contact The Boeing Company for availability and price information.
B. Industry Support Information
Boeing warranty remedies are not available for the inspection and/or repair procedures given in this
service bulletin.
C. Parts Necessary for Each Airplane
1. Kits/Parts
To get the kits/parts shown below, refer to Paragraph 2.A., Material - Price and Availability.
NOTE: One 015U1848-2 top kit and the items shown in Paragraph 2.C.2., Parts and Materials
Supplied by the Operator, are necessary for each airplane. The Top Kit is divided into
Figure kits for each installation figure shown in the table below.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
27 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 28

If a 015U1848-1 top kit has previously been purchased but not installed, one 015U1848-3
supplemental kit can be added to the 015U1848-1 top kit to give all the parts necessary
for a 015U1848-2 top kit.
If a 015U1848-2 top kit is not available, one 015U1848-1 top kit and one 015U1848-3
supplemental kit can be added together to give all the parts necessary for a 015U1848-2
top kit. Refer to APPENDIX A for 015U1848-1 top kit parts list and figure kits.
Figure Kit
191816151413Top Kit
111111015U1848-2
Figure Kit
2620Top Kit
11015U1848-2
ALL
KIT 015U1848-2
NOTES
Existing Part
NumberName
Figure
New Part Number
191816151413
QTY
-141U8008-11TEE1141U0058-11
-141U8008-12TEE1141U0058-12
-141U8008-1CLIP1141U0058-13
-SPLICE PLATE1141U0058-15
-SPLICE STRAP1141U0058-17
-SPLICE STRAP1141U0058-19
-SPLICE STRAP1141U0058-20
-141U8008-2ANGLE1141U8008-2
(c)141U8008-3TEE1141U8008-3
(c)141U8008-4TEE1141U8008-4
(c)141U8008-503TEE1141U8008U19
(c)141U8008-504TEE1141U8008U20
(c)141U8008-5ANGLE1141U8008U5
(c)141U8008-6ANGLE1141U8008U6
(c)141U8011-1,
141U8012-1
INTERCOSTAL1141U8012U1
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
28 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 29

ALL
KIT 015U1848-2
NOTES
Existing Part
NumberName
Figure
New Part Number
191816151413
QTY
(c)141U8011-2,
141U8012-2
INTERCOSTAL1141U8012U2
-65B07603-24FILLER265B07603-24
-65B07603-25FILLER265B07603-25
-65B07603-501FILLER-RADIUS265B07603-501
-65B07603-34WEB165B07603-58
-65B07612-13FILLER1165B07612-13
-65B07617-19SHIM265B07617-19
(b)BOLT, PROTRUD-
ING HD
4BACB30MY10K4X
(b)BOLT, PROTRUD-
ING HD
4BACB30MY10K6X
(b)BOLT, PROTRUD-
ING HD
6BACB30MY8K10X
(a) (b)BOLT, PROTRUD-
ING HD
945BACB30MY8K4X
(a) (b)BOLT, PROTRUD-
ING HD
927BACB30MY8K5X
(a) (b)BOLT, PROTRUD-
ING HD
1634BACB30MY8K6X
(a) (b)BOLT, PROTRUD-
ING HD
742BACB30MY8K7X
(b)BOLT, PROTRUD-
ING HD
9BACB30MY8K8X
(a) (b)BOLT, PROTRUD-
ING HD
18BACB30MY8K9X
(b)BOLT, HEX HEAD2BACB30NM3K10X
(b)BOLT, HEX HEADBACB30NM3K11X
(a) (b)BOLT, HEX HEAD13BACB30NM3K12X
(b)BOLT11BACB30NM3K4
(b)BOLT2BACB30NM3K7
(b)BOLT, HEX HEAD2BACB30NR4K10X
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
29 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 30

ALL
KIT 015U1848-2
NOTES
Existing Part
NumberName
Figure
New Part Number
191816151413
QTY
(b)BOLT22BACB30NR4K11X
(BACB30US4K12X
optional)
(b)BOLT, HEX HEAD2BACB30NR4K12X
(b)BOLT, HEX HEAD6BACB30NR4K6
(b)BOLT, HEX HEAD2BACB30NR4K6X
(b)BOLT, HEX HEAD2BACB30NR4K8X
(b)BOLTBACB30NW6K4
(a) (b)BOLT, 100 DEG
HEX DR
3737BACB30NW6K4X
(b)BOLT, HILOKBACB30NW6K5
(a) (b)BOLT, 100 DEG
HEX DR
8422BACB30NW6K5X
(b)BOLT, 100 DEG
HEX DR
77BACB30NW6K5Y
(b)HI-LOKBACB30NW6K6
(b)BOLT, 100 DEG
HEX DR
822BACB30NW6K6X
(b)BOLTBACB30NW6K7
(b)BOLT, 100 DEG
HEX DR
8BACB30NW6K7X
(b)HI-LOKBACB30NW6K8
(a) (b)BOLT, PROTRUD-
ING HD
20834BACB30NX6K4X
(a) (b)BOLT, PROTRUD-
ING HD
1356BACB30NX6K5X
(a) (b)BOLT, PROTRUD-
ING HD
21011BACB30NX6K6X
(a) (b)BOLT, PROTRUD-
ING HD
11BACB30NX6K6Y
(b)BOLT, PROTRUD-
ING HD
8111BACB30NX6K7X
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
30 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 31

ALL
KIT 015U1848-2
NOTES
Existing Part
NumberName
Figure
New Part Number
191816151413
QTY
(a) (b)BOLT, PROTRUD-
ING HD
97BACB30NX6K8X
(a) (b)BOLT, PROTRUD-
ING HD
452BACB30NX6K9X
(b)BOLT, PROTRUD-
ING HD
2BACB30NX8K11X
(b)BOLT, PROTRUD-
ING HD
2BACB30NX8K8X
(b)BOLT, 100 DEG
HEAD
22BACB30VF3K5
(a) (b)BOLT26961919BACB30VT6K4
(b)BOLT622BACB30VT6K5
(b)BOLT6BACB30VT6K6
(a) (b)BOLT13BACB30VT6K8
(a) (b)BOLT613BACB30VT8K4
(a) (b)HI-LOK2011BACB30VT8K6
(b)BOLT, 100 DEG
HEX DR
BACB30YP6K3
(b)BOLT, 100 DEG
HEX DR
BACB30YP6K4
(a)COLLAR11BACC30AC6
(a)COLLAR235821BACC30BH6
-COLLAR22BACC30BH8
(a)COLLAR2610312121BACC30BL6
(a)COLLAR63311BACC30BL8
-COLLAR8BACC30M10
(a)COLLAR1025151BACC30M6
(a)COLLAR21603346BACC30M8
(a)COLLAR77BACC30R6
-FILLER2BACF3F013R046NN
-TAPERED FILLER11BACF3T01F35-20
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
31 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 32

ALL
KIT 015U1848-2
NOTES
Existing Part
NumberName
Figure
New Part Number
191816151413
QTY
-NUT22BACN10HR4CD
(a)NUT15BACN10JC3C
(a)NUT13BACN10JC4C
-NUT6BACN10JC4CM
(a)NUT21533BACN10YR3CD
-SHIM, LAMINAT-
ED
4BACS40R008C008F
-SHIM, LAMINAT-
ED
411BACS40R008C020F
-SHIM,LAMINATED2BACS40R008D031F
-SHIM, LAMINAT-
ED
2BACS40R010B010F
-SHIM LAMINATED2BACS40R020C030F
-SHIM ,LAMINAT-
ED
11BACS40R020C035F
-WASHER211BACW10BN3AC
(a)WASHER, PLAIN
AND COUNTER-
SUNK
1522BACW10BP31NPK
(a)WASHER21511BACW10BP3PK
This washer
is counter-
sunk.
WASHER, PLAIN22BACW10BP41CK
(a)WASHER, PLAIN128BACW10BP41NPK
-WASHER, PLAIN
AND COUNTER-
SUNK
22BACW10BP41PK
-WASHER, PLAIN6BACW10BP4NPK
(a)WASHER1734BACW10CA104CCU
(a)WASHER1734BACW10CA31CVU
-WASHER, SELF-
ALIGN
22BACW10CA41CVU
-WASHER22BACW10CA5CCU
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
32 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 33

ALL
KIT 015U1848-2
NOTES
Existing Part
NumberName
Figure
New Part Number
191816151413
QTY
(a) There are more parts than are necessary.
(b) If grip length shown is not available at Boeing, fasteners supplied in kits may be one grip length longer
than indicated. Also, if any fastener part numbers listed are not available or have been superseded, sub-
stitute fasteners may be supplied in kits. Boeing Document D590 and Boeing Drawing 012W6100 are
used to determine the part numbers used as substitutes.
(c) To make installation easier, some Boeing parts are sent in an ‘interim’ configuration. Boeing will identify
these interim configurations with a 'U', 'W' or 'Y' in place of the '-' (dash) in the part number. Interim parts
are changed to the ‘dash’ configuration when installed as given in the Accomplishment Instructions of this
service bulletin. Refer to Boeing Drawing 005W0900 "INTERIM PARTS – SPARES" and Service Letter
747-SL-00-018 for more information.
ALL
KIT 015U1848-2
NOTES
Existing Part Num-
berName
Figure
New Part Number
2620
QTY
-141U8008-11TEE141U0058-11
-141U8008-12TEE141U0058-12
-141U8008-1CLIP141U0058-13
-SPLICE PLATE141U0058-15
-SPLICE STRAP141U0058-17
-SPLICE STRAP141U0058-19
-SPLICE STRAP141U0058-20
-141U8008-2ANGLE141U8008-2
-141U8008-3TEE141U8008-3
-141U8008-4TEE141U8008-4
-141U8008-503TEE141U8008U19
-141U8008-504TEE141U8008U20
-141U8008-5ANGLE141U8008U5
-141U8008-6ANGLE141U8008U6
-141U8011-1,
141U8012-1
INTERCOSTAL141U8012U1
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
33 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 34

ALL
KIT 015U1848-2
NOTES
Existing Part Num-
berName
Figure
New Part Number
2620
QTY
-141U8011-2,
141U8012-2
INTERCOSTAL141U8012U2
-65B07603-24FILLER65B07603-24
-65B07603-25FILLER65B07603-25
-65B07603-501FILLER-RADIUS65B07603-501
-65B07603-34WEB65B07603-58
-65B07612-13FILLER65B07612-13
-65B07617-19SHIM65B07617-19
-BOLT, PROTRUDING HDBACB30MY10K4X
-BOLT, PROTRUDING HDBACB30MY10K6X
-BOLT, PROTRUDING HDBACB30MY8K10X
-BOLT, PROTRUDING HDBACB30MY8K4X
-BOLT, PROTRUDING HDBACB30MY8K5X
-BOLT, PROTRUDING HDBACB30MY8K6X
-BOLT, PROTRUDING HDBACB30MY8K7X
-BOLT, PROTRUDING HDBACB30MY8K8X
-BOLT, PROTRUDING HDBACB30MY8K9X
-BOLT, HEX HEADBACB30NM3K10X
(a) (b)BOLT, HEX HEAD11BACB30NM3K11X
-BOLT, HEX HEADBACB30NM3K12X
-BOLTBACB30NM3K4
-BOLTBACB30NM3K7
-BOLT, HEX HEADBACB30NR4K10X
-BOLTBACB30NR4K11X
(BACB30US4K12X op-
tional)
-BOLT, HEX HEADBACB30NR4K12X
-BOLT, HEX HEADBACB30NR4K6
-BOLT, HEX HEADBACB30NR4K6X
-BOLT, HEX HEADBACB30NR4K8X
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
34 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 35

ALL
KIT 015U1848-2
NOTES
Existing Part Num-
berName
Figure
New Part Number
2620
QTY
(b)BOLT15BACB30NW6K4
-BOLT, 100 DEG HEX DRBACB30NW6K4X
(b)BOLT, HILOK2BACB30NW6K5
-BOLT, 100 DEG HEX DRBACB30NW6K5X
-BOLT, 100 DEG HEX DRBACB30NW6K5Y
(b)HI-LOK6BACB30NW6K6
-BOLT, 100 DEG HEX DRBACB30NW6K6X
(b)BOLT3BACB30NW6K7
-BOLT, 100 DEG HEX DRBACB30NW6K7X
(b)HI-LOK3BACB30NW6K8
-BOLT, PROTRUDING HDBACB30NX6K4X
-BOLT, PROTRUDING HDBACB30NX6K5X
-BOLT, PROTRUDING HDBACB30NX6K6X
-BOLT, PROTRUDING HDBACB30NX6K6Y
-BOLT, PROTRUDING HDBACB30NX6K7X
-BOLT, PROTRUDING HDBACB30NX6K8X
-BOLT, PROTRUDING HDBACB30NX6K9X
-BOLT, PROTRUDING HDBACB30NX8K11X
-BOLT, PROTRUDING HDBACB30NX8K8X
-BOLT, 100 DEG HEADBACB30VF3K5
-BOLTBACB30VT6K4
-BOLTBACB30VT6K5
-BOLTBACB30VT6K6
-BOLTBACB30VT6K8
-BOLTBACB30VT8K4
-HI-LOKBACB30VT8K6
(b)BOLT, 100 DEG HEX DR2BACB30YP6K3
(b)BOLT, 100 DEG HEX DR4BACB30YP6K4
-COLLARBACC30AC6
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
35 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 36

ALL
KIT 015U1848-2
NOTES
Existing Part Num-
berName
Figure
New Part Number
2620
QTY
-COLLARBACC30BH6
-COLLARBACC30BH8
-COLLAR8BACC30BL6
-COLLARBACC30BL8
-COLLARBACC30M10
-COLLAR40BACC30M6
-COLLARBACC30M8
-COLLARBACC30R6
-FILLERBACF3F013R046NN
-TAPERED FILLERBACF3T01F35-20
-NUTBACN10HR4CD
(a)NUT11BACN10JC3C
-NUTBACN10JC4C
-NUTBACN10JC4CM
-NUTBACN10YR3CD
-SHIM, LAMINATEDBACS40R008C008F
-SHIM, LAMINATEDBACS40R008C020F
-SHIM,LAMINATEDBACS40R008D031F
-SHIM, LAMINATEDBACS40R010B010F
-SHIM LAMINATEDBACS40R020C030F
-SHIM ,LAMINATEDBACS40R020C035F
-WASHERBACW10BN3AC
(a)WASHER, PLAIN AND
COUNTERSUNK
11BACW10BP31NPK
-WASHERBACW10BP3PK
This washer is
countersunk.
WASHER, PLAINBACW10BP41CK
-WASHER, PLAINBACW10BP41NPK
-WASHER, PLAIN AND
COUNTERSUNK
BACW10BP41PK
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
36 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 37

ALL
KIT 015U1848-2
NOTES
Existing Part Num-
berName
Figure
New Part Number
2620
QTY
-WASHER, PLAINBACW10BP4NPK
-WASHERBACW10CA104CCU
-WASHERBACW10CA31CVU
-WASHER, SELF-ALIGNBACW10CA41CVU
-WASHERBACW10CA5CCU
(a) There are more parts than are necessary.
(b) If grip length shown is not available at Boeing, fasteners supplied in kits may be one grip length longer
than indicated. Also, if any fastener part numbers listed are not available or have been superseded, sub-
stitute fasteners may be supplied in kits. Boeing Document D590 and Boeing Drawing 012W6100 are
used to determine the part numbers used as substitutes.
KIT 015U1848-3
NotesNameQTYNew Part Number
(b)BOLT2BACB30NM3K4
(b)BOLT2BACB30NM3K7
(b)BOLT15BACB30NW6K4
(b)BOLT, HILOK2BACB30NW6K5
(b)HI-LOK6BACB30NW6K6
(b)BOLT3BACB30NW6K7
(b)HI-LOK3BACB30NW6K8
(b)BOLT, 100 DEG HEAD2BACB30VF3K5
(a) (b)BOLT38BACB30VT6K4
(b)BOLT4BACB30VT6K5
(a) (b)HI-LOK22BACB30VT8K6
(b)BOLT, 100 DEG HEX DR2BACB30YP6K3
(b)BOLT, 100 DEG HEX DR4BACB30YP6K4
(a)COLLAR50BACC30BL6
(a)COLLAR22BACC30BL8
(a)NUT21BACN10YR3CD
(a)WASHER4BACW10BN3AC
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
37 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 38

KIT 015U1848-3
NotesNameQTYNew Part Number
-WASHER, PLAIN AND COUN-
TERSUNK
2BACW10BP31NPK
(a)WASHER19BACW10BP3PK
(a) There are more parts than are necessary.
(b) If grip length shown is not available at Boeing, fasteners supplied in kits may be one grip length longer
than indicated. Also, if any fastener part numbers listed are not available or have been superseded, sub-
stitute fasteners may be supplied in kits. Boeing Document D590 and Boeing Drawing 012W6100 are
used to determine the part numbers used as substitutes.
2. Parts and Materials Supplied by the Operator
NotesNameQTYPart Number /
Specification
(a)Chemical Conversion Coating4 ozTYPE 2, CLASS A
(b)Primer4 ozBMS 10-11, TYPE I
(b)Sealant8 ozBMS 5-95, CLASS B
This part is optional. (c)BRACKET ASSY1SB747-53A2784-1
(d)NUT109BACN10YR3CD
(e)WASHER109BACW10BP3PK
(f)NUT109MS21042L3
(f)NUT109MS21043L3
(a) Refer to SOPM 20-43-03 for material source.
(b) See the Qualified Products List at the end of the Boeing Material Specification (BMS) for supplier data.
(c) Fabricate from 2024-T0 Aluminum, size 0.040 x 3.5 x 8.0 inch as shown in FIGURE 17.
(d) This part is optional and can be used with washer BACW10BP3PK in place of a BACC30BL6 collar in
FIGURE 14, FIGURE 15, FIGURE 16, FIGURE 18, FIGURE 19.
(e) This part is optional and can be used with nut BACN10YR3CD in place of a BACC30BL6 collar in FIGURE
14, FIGURE 15, FIGURE 16, FIGURE 18, FIGURE 19.
(f) This part is optional and can be used in place of BACN10YR3CD in FIGURE 14, FIGURE 15, FIGURE
16, FIGURE 18, FIGURE 19.
If a 015U1848-1 top kit is used to accomplish this service bulletin and the 015U1848-3 supplemental
kit cannot be supplied by Boeing, it may be necessary for the parts identified in the 015U1848-3
supplemental kit to be supplied by the operator. Refer to Paragraph 2.C.1., Kits/Parts.
3. Parts Modified and Reidentified
The parts shown below are changed as shown in this service bulletin. The quantity (QTY) is the
number of parts changed on each airplane.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
38 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 39

NotesNew Part NumberNameQTYExisting Part
Number
(a)(b)BRACKET ASSY1232U1361-72
(a) The change given in this service bulletin is optional to fabricating a new bracket assembly.
(b) There is no equivalent Boeing part number for the changed part. Identify on the part that
the change given in this service bulletin was made.
4. Parts Removed and Not Replaced
None.
D. Parts Necessary to Change Spares
None.
E. Special Tooling - Price and Availability
None.
F. Special Tooling Necessary to do this Service Bulletin
No special tools or equipment are necessary to do the change in this service bulletin. But, maintenance
and overhaul tools in the manuals given in Paragraph 1.J., References, can be necessary. Examine
operator tool supply to make sure all necessary tools are available.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
39 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 40

Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
40 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT
BLANK PAGE

### Page 41

3.    ACCOMPLISHMENT INSTRUCTIONS
A. GENERAL INFORMATION
CAUTION: KEEP THE WORK AREA, WIRES AND ELECTRICAL BUNDLES CLEAN OF METAL
PARTICLES OR CONTAMINATION WHEN YOU USE TOOLS. UNWANTED MATERIAL,
METAL PARTICLES OR CONTAMINATION CAUGHT IN WIRE BUNDLES CAN CAUSE
DAMAGE TO THE BUNDLES. DAMAGED WIRE BUNDLES CAN CAUSE SPARKS OR
OTHER ELECTRICAL DAMAGE.
NOTE: 1. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for
definition of the acronyms.
2. Obey all of the warnings and cautions given in the specified manual sections.
3. Unless shown differently, these dimensions and tolerances are used:
– Linear dimensions are in inches
– Tolerance on linear dimensions, other than rivet and bolt edge margins, is plus
or minus 0.03 inch
– Hole dimensions for standard solid rivets are given in 747 SRM, Chapter 51
– Torque limits to tighten nuts and bolts are given in 747 SRM, Chapter 51
4. For approved fastener and process material substitutions, refer to 747 SRM, Chapter
51. Alternate fasteners are given in 747 SRM Chapter 51 and Boeing Drawing
012W6100.
5. Refer to the SWPM 20-10-11 and SWPM 20-10-12 for the wire installation procedures,
and SWPM 20-10-19 for the wire separation requirements.
6. If the length of any fastener specified in this service bulletin does not meet the
installation standards given in SRM Chapter 51, then a fastener of the same
specification, or an approved substitute, with a length which meets the installation
standards given in SRM Chapter 51 may be used.
7. A Detailed Inspection is defined as: An intensive examination of a specific item,
installation, or assembly to detect damage, failure, or irregularity. Available lighting
is normally supplemented with a direct source of good lighting at an intensity deemed
appropriate. Inspection aids such as mirrors, magnifying lenses, etc. may be
necessary. Surface cleaning and elaborate procedures may be required.
8. A General Visual Inspection is defined as: A visual examination of an interior or
exterior area, installation or assembly to detect obvious damage, failure or irregularity.
This level of inspection is made from within touching distance unless otherwise
specified. A mirror may be necessary to ensure visual access to all surfaces in the
inspection area. This level of inspection is made under normal available lighting
conditions such as daylight, hangar lighting, flashlight or drop-light and may require
removal or opening of access panels or doors. Stands, ladders or platforms may be
required to gain proximity to the area being checked.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
41 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 42

9. These work instructions refer to procedures included in other Boeing documents.
When the words "refer to" are used and the operator has an accepted alternative
procedure, the accepted alternative procedure can be used. When the words "in
accordance with" are included in the instruction, the procedure in the Boeing document
must be used.
10. Boeing Service Letter 747-SL-51-048, Damage Reporting and Repair Plan/Design
Guidelines, is an acceptable procedure to request information from Boeing for
additional structural repair instructions. The Service Letter describes what information
must be provided to Boeing before a structural repair can be provided.
11. The instructions in Paragraph 3.B., Work Instructions and the figures can include
operation of tools or test equipment. Boeing Engineering Tool Drawings, the Illustrated
Tool and Equipment Manual, and the Special Tool and Ground Handling Drawing
Index contain data on versions of the tools or test equipment that you can use. It is
permitted to use replaced tools. It is not permitted to use superseded tools.
12. If it is necessary to remove more parts for access, you can remove those parts. If
you can get access without removing identified parts, it is not necessary to remove
all of the identified parts. Jacking and shoring limitations must be observed.
13. Where the work instructions include installation of a kept part, a new or serviceable
part with the same part number can be installed as an alternative to the kept part.
14. Some Boeing parts are supplied in a temporary configuration. Those parts are
identified with a 'U', 'W', or 'Y' in place of the '-' (dash) in the part number. It is
permitted to install parts identified with a 'U', 'W', or 'Y' as an alternative to the '-'
(dash) part number. Boeing Drawing 005W0900 contains more data.
15. The compliance times for the actions in Paragraph 3.B., WORK INSTRUCTIONS
are in Paragraph 1.E., Compliance.
16. When the wire bundle inspections and/or repairs disrupt the wire continuity or result
in disconnecting a connector, do the appropriate system functional test for the wire
bundles which have been repaired or the connectors which have unmated in
accordance with the appropriate section of the 747 AMM.
17. The maximum gap before fastener pull-up is 0.005 inch. If a gap exceeds 0.005 inch,
shim as required. The maximum allowable shim thickness is 0.032 inch unless
otherwise stated.
18. Unless otherwise specified in the service bulletin Figures, maintain 2D minimum
edge margin on all parts. 1.7D minimum edge margin or edge margins in accordance
with 747-400 SRM 51-40-06, 747-400F SRM 51-40-06 or 747-400SF SRM 51-40-06
are acceptable if limited by adjacent structure.
19. Unless otherwise specified in the service bulletin Figures, it is acceptable to install
fasteners that are 1/32 inch larger than the existing production fasteners. This does
not apply to fastener locations that are already oversized during accomplishment of
the STA 320 crown frame web replacement instructions in this service bulletin.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
42 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 43

20. For all parts that are installed using permanent fasteners, install parts wet with BMS
5-95, CLASS B sealant applied between mating surfaces. Install all permanent
fasteners and fasteners common to the skin wet with BMS 5-95, CLASS B sealant.
21. Refer to Appendix A for Top Kit.
B. WORK INSTRUCTIONS
Group 1, Configuration 1, 3:
PART 1: ACCESS
1. Remove the pilots' seats as necessary. Refer to 747-400 AMM 25-11-01 as an accepted procedure.
2. Get access to the web and intercostal in accordance with FIGURE 1.
3. Do PART 2.
Group 1, Configuration 1, 3:
PART 2: MEASURE WEB THICKNESS
1. Measure the thickness of the web in accordance with FIGURE 2.
a. If the web is 0.136 inch thick or greater, no further action is required. Do PART 6.
b. If the web is less than 0.136 inch thick and no repair doubler is installed on the web, do PART
3.
c. If the web is less than 0.136 inch thick and a repair doubler is installed on the web, do PART
4.
Group 1, Configuration 1, 3:
PART 3: LESS THAN 0.136 INCH THICK WEB WITH NO REPAIR DOUBLER INSTALLED
1. Do a detailed inspection for any crack and a general visual inspection for missing fasteners of the
STA 320 crown frame in accordance with FIGURE 3.
a. If any crack is found in the upper or lower chord, contact The Boeing Company for repair
instructions and do the repair.
b. If any crack is found in the web, do PART 5: WEB REPLACEMENT.
c. If no crack is found in the web, do one of the following options:
NOTE: Option 2 allows operators to do a HFEC inspection of the web. If no crack is found,
web replacement can be delayed. Refer to Paragraph 1.E., Compliance.
(1) OPTION 1: Do PART 5: WEB REPLACEMENT.
(2) OPTION 2: Do a Surface HFEC inspection for any crack in the web in accordance with
FIGURE 5.
(a) If any crack is found, do PART 5: WEB REPLACEMENT.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
43 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 44

(b) If no crack is found, do the following:
1) If the general visual inspection determined that any fastener was missing, install
new fasteners at locations where fasteners are missing. Install fasteners in
accordance with web replacement FIGURE 13, except install a nominal size
fastener, not an oversize fastener.
2) Apply TYPE 2, CLASS A chemical conversion coating to any bare aluminum.
Apply BMS 10-11, TYPE I primer (two coats) to the visible surfaces of all new
parts and of any existing parts in accordance with FIGURE 28.
3) Do PART 5: WEB REPLACEMENT at the time given in Paragraph 1.E.,
Compliance.
Group 1, Configuration 1, 3:
PART 4: LESS THAN 0.136 INCH THICK WEB WITH REPAIR DOUBLER INSTALLED
1. Do a detailed inspection for any crack in the upper chord and lower chord of the STA 320 crown
frame in accordance with FIGURE 27.
NOTE: It is not necessary to inspect the web for cracks or to inspect for missing fasteners.
a. If any crack is found in the upper or lower chord, contact The Boeing Company for repair
instructions and do the repair.
b. Do PART 5: WEB REPLACEMENT.
Group 1, Configuration 1, 3:
PART 5: WEB REPLACEMENT
1. Remove access panels in accordance with FIGURE 6.
2. Remove straps, tees, angles, stiffeners, clip and bracket in accordance with FIGURE 7.
a. Remove fasteners common to the forward edge of the upper chord and the skin as necessary
to allow fasteners common to the STA 320 frame web to be removed in accordance with
FIGURE 25.
3. Chamfer/trim and inspect the sill chord as necessary and remove the lower chord in accordance
with FIGURE 8.
a. If any crack is found in the sill chord, contact The Boeing Company for work instructions and
do the work.
4. Remove the following intercostals in accordance with FIGURE 9:
– LBL 7.5, between STA 320 and STA 340
– LBL 15.0, between STA 320 and STA 340
5. Remove the following intercostals in accordance with FIGURE 10:
– RBL 7.5, between STA 320 and STA 340
– RBL 15.0, between STA 320 and STA 340
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
44 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 45

6. Remove the existing web in accordance with FIGURE 11.
a. Remove fasteners common to the forward edge of the upper chord and the skin as necessary
to allow fasteners common to the STA 320 frame web to be removed in accordance with
FIGURE 25.
7. Do Surface HFEC and Open Hole HFEC inspections of the lower chord in accordance with FIGURE
12.
a. If any crack is found around a fastener hole, contact The Boeing Company for repair instructions
and do the repair.
8. Install the new web in accordance with FIGURE 13.
9. Install the RBL 15.0 intercostal between STA 320 and STA 340 in accordance with FIGURE 14.
10. Install the LBL 15.0 intercostal between STA 320 and STA 340 in accordance with FIGURE 15.
11. Install the lower chord and splice in accordance with FIGURE 16.
12. Modify the existing or make a new dripshield bracket in accordance with FIGURE 17.
13. Install straps, tees, angles, stiffeners, clip and bracket in accordance with FIGURE 18.
14. Install new intercostals, tees and straps in accordance with FIGURE 19.
15. Install fasteners, if removed, common to the forward edge of the upper chord and the skin in
accordance with FIGURE 26.
16. Install access panels in accordance with FIGURE 20.
17. Apply TYPE 2, CLASS A chemical conversion coating to any bare aluminum. Apply BMS 10-11,
TYPE I primer (two coats) to the visible surfaces of all new parts and of any existing parts in
accordance with FIGURE 28.
18. Do PART 6: CLOSE ACCESS.
Group 1, Configuration 1, 3:
PART 6: CLOSE ACCESS
1. Close access in accordance with FIGURE 21.
2. Install the pilots' seats as necessary. Refer to 747-400 AMM 25-11-01 as an accepted procedure.
3. Put the airplane back to a serviceable condition.
4. If PART 5: WEB REPLACEMENT has been done, do PART 7: POST WEB REPLACEMENT
INSPECTIONS at the times given in Paragraph 1.E., Compliance.
PART 7: POST WEB REPLACEMENT INSPECTIONS
1. Remove the pilots' seats as necessary. Refer to 747-400 AMM 25-11-01 as an accepted procedure.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
45 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 46

2. Get access to the web in accordance with FIGURE 1.
3. Remove access panels in accordance with FIGURE 22.
4. Do detailed inspections of the web, upper chord, lower chord and lower chord splice for any crack
in accordance with FIGURE 23.
NOTE: When inspections in accordance with FAA AD 2009-19-05 start, the STA 320 Post Web
Replacement Inspections are not required. FAA AD 2009-19-05 is related to Boeing
Service Bulletin 747-53A2753.
a. If no crack is found, repeat the post web replacement inspection at the time given in Paragraph
1.E., Compliance.
b. If any crack is found, contact The Boeing Company for repair instructions and do the repair.
5. Install access panels in accordance with FIGURE 24.
6. Close access in accordance with FIGURE 21.
7. Install the pilots' seats as necessary. Refer to 747-400 AMM 25-11-01 as an accepted procedure.
Group 1, Configuration 2:
PART 8: WEB REPLACEMENT (MORE WORK REQUIRED)
1. Get access.
a. Remove the pilots' seats as necessary. Refer to 747-400 AMM 25-11-01 as an accepted
procedure.
b. Get access to the web and intercostal in accordance with FIGURE 1.
2. Replace web.
a. Remove access panels in accordance with FIGURE 6.
b. Remove straps, tees, angles, stiffeners, clip and bracket in accordance with FIGURE 7.
(1) Remove fasteners common to the forward edge of the upper chord and the skin as
necessary to allow fasteners common to the STA 320 frame web to be removed in
accordance with FIGURE 25.
c. Chamfer/trim and inspect the sill chord as necessary and remove the lower chord in accordance
with FIGURE 8.
(1) If any crack is found in the sill chord, contact The Boeing Company for work instructions
and do the work.
d. Remove the following intercostals in accordance with FIGURE 9:
– LBL 7.5, between STA 320 and STA 340
– LBL 15.0, between STA 320 and STA 340
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
46 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 47

e. Remove the following intercostals in accordance with FIGURE 10:
– RBL 7.5, between STA 320 and STA 340
– RBL 15.0, between STA 320 and STA 340
f. Remove the existing web in accordance with FIGURE 11:
(1) Remove fasteners common to the forward edge of the upper chord and the skin as
necessary to allow fasteners common to the STA 320 frame web to be removed in
accordance with FIGURE 25.
g. Do Surface HFEC and Open Hole HFEC inspections for cracking of the lower chord in
accordance with FIGURE 12.
(1) If any crack is found around a fastener hole, contact The Boeing Company for repair
instructions and do the repair.
h. Install the new web in accordance with FIGURE 13.
i. Install the RBL 15.0 intercostal between STA 320 and STA 340 in accordance with FIGURE
14.
j. Install the LBL 15.0 intercostal between STA 320 and STA 340 in accordance with FIGURE
15.
k. Install the lower chord and splice in accordance with FIGURE 16.
l. Modify the existing or make a new dripshield bracket in accordance with FIGURE 17.
m. Install straps, tees, angles, stiffeners, clip and bracket in accordance with FIGURE 18.
n. Install new intercostals, tees and straps in accordance with FIGURE 19.
o. Install fasteners, if removed, common to the forward edge of the upper chord and the skin in
accordance with FIGURE 26.
p. Install access panels in accordance with FIGURE 20.
q. Apply TYPE 2, CLASS A chemical conversion coating to any bare aluminum. Apply BMS
10-11, TYPE I primer (two coats) to the visible surfaces of all new parts and of any existing
parts in accordance with FIGURE 28.
3. Close access.
a. Close access in accordance with FIGURE 21.
b. Install the pilots' seats as necessary. Refer to 747-400 AMM 25-11-01 as an accepted
procedure.
c. Put the airplane back to a serviceable condition.
4. After PART 8, step 2 WEB REPLACEMENT has been done, do the PART 7: POST WEB
REPLACEMENT INSPECTIONS at the times given in Paragraph 1.E., Compliance.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2: August 20, 2015
47 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 48 (OCR)

BOEING SERVICE BULLETIN 747-53A2784
ALERT  ALERT
STA 360 -
STA 300 -
• 0000
1698738
FIGURE 1: STA 300 TO STA 340 CROWN - ACCESS
(SHEET 1 OF 3)
Original Issue: August 27, 2009
Revision 2 August 20, 2015  Export Controlled ECCN: 9E991 - BOEING  747-53A2784
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.  48 of 248

### Page 49 (OCR)

BOEING SERVICE BULLETIN 747-53A2784
ALERT  ALERT
STA
360
STA
340
STA
_320
STA
300
TYPICAL
1698740
FIGURE 1: STA 300 TO STA 340 CROWN - ACCESS
(SHEET 2 OF 3)
Original Issue: August 27, 2009
Revision 2 August 20, 2015  PROPRIETARY - Copyright © Unpublished  Export Controlled ECCN: 9E991 - BOEING  747-53A2784
Work - See page 1 for details.  49 of 248

### Page 50

The step numbers shown below agree with the numbers shown in the circle symbols in the figure.
MORE DATAQTYIDENTIFICATIONNAMETASKSTEP
(a) (b)--Ceiling liningRemove / Keep1
(a) (c)--Sidewall liningRemove / Keep2
(a) (d) (g)--Overhead equipment
panels
Remove / Keep3
(a) (e) (g)--Disconnect PanelsRemove / Keep
(a) (f) (g)--Wire bundlesRemove / Keep
(a) (h)--Air conditioningRemove / Keep4
(a)--Overhead equipment
support structure
Remove / Keep5
(a) (i)--Dripshields and Insula-
tion
Remove / Keep6
(j)--Any other obstructionsRemove / Keep7
(a) Remove parts as necessary to get access to the STA 320 crown and the BL 0 intercostal from STA 320
to STA 340 for inspection and the STA 300 to STA 340 crown for STA 320 crown frame web replacement.
(b) Refer to 747-400 AMM 25-14-00 and 747-400 AMM 25-22-00 as an accepted procedure.
(c) Remove the sidewall lining from the window posts shown. Refer to 747-400 AMM 25-15-00 and 747-400
AMM 25-21-00 as an accepted procedure.
(d) Remove overhead equipment panels from STA 300 to STA 360. Disconnect any wires as necessary.
(e) Remove disconnect panels behind the removed overhead equipment panels.
(f) Remove wire bundles common to the removed overhead equipment panels. Remove all remaining overhead
wire bundles from STA 300 to STA 340.
(g) Refer to 747-400 AMM 31-00-00 as an accepted procedure.
(h) Remove air conditioning equipment as required to allow removal of the overhead equipment support
structure. Remove all remaining air conditioning equipment between STA 300 and STA 340.
(i) Remove dripshields and insulation from STA 300 to STA 340. Refer to 747-400 AMM 25-14-01 as an
accepted procedure.
(j) Remove any other parts as necessary to get access to the STA 320 crown and the BL 0 intercostal from
STA 300 to STA 340 for inspection and the STA 300 to STA 340 crown for STA 320 crown frame web
replacement. Refer to 747-400 AMM for accepted procedures.
FIGURE 1: STA 300 TO STA 340 CROWN - ACCESS
(SHEET 3 OF 3)
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2 August 20, 2015
50 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 51 (OCR)

BOEING SERVICE BULLETIN 747-53A2784
ALERT  ALERT
This Figure applies only to: Group 1, Configuration 1, 3.
BLO  _ STA 340
_ STA 320
1698742
FIGURE 2: STA 320 CROWN FRAME - WEB THICKNESS MEASUREMENT
(SHEET 1 OF 2)
Original Issue: August 27, 2009
Revision 2 August 20, 2015  Export Controlled ECCN: 9E991 - BOEING  747-53A2784
PROPRIETARY - Copyright © Unpublished  Work - See page 1 for details.  51 of 248

### Page 52

The step numbers shown below agree with the numbers shown in the circle symbols in the figure.
More DataQtyIdentificationNameTaskStep
(a) (b)--WEBMeasure1
(a) Remove paint if/as required. Refer to 747-400 AMM 51-21-01 as an accepted procedure.
(b) Measure the thickness of the web.
FIGURE 2: STA 320 CROWN FRAME - WEB THICKNESS MEASUREMENT
(SHEET 2 OF 2)
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2 August 20, 2015
52 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 53 (OCR)

BOEING SERVICE BULLETIN 747-53A2784
ALERT  ALERT
This Figure applies only to: Group 1, Configuration 1, 3.
BLO  _ STA 340
_STA 320
1698743
FIGURE 3: STA 320 CROWN FRAME - INSPECTION
(SHEET 1 OF 4)
Original Issue: August 27, 2009
Revision 2 August 20, 2015  PROPRIETARY - Copyright © Unpublished  Export Controlled ECCN: 9E991 - BOEING  747-53A2784
Work - See page 1 for details.  53 of 248

### Page 54 (OCR)

BOEING SERVICE BULLETIN 747-53A2784
ALERT  ALERT
B
BL O
RBL
48  30.0
STA
320
LBL
30.0
SOME STRUCTURE NOT SHOWN FOR CLARITY
1698744
FIGURE 3: STA 320 CROWN FRAME - INSPECTION
(SHEET 2 OF 4)
Original Issue: August 27, 2009
Revision 2 August 20, 2015  Export Controlled ECCN: 9E991 - BOEING  747-53A2784
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.  54 of 248

### Page 55

FIGURE 3: STA 320 CROWN FRAME - INSPECTION
(SHEET 3 OF 4)
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2 August 20, 2015
55 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 56

The step numbers shown below agree with the numbers shown in the circle symbols in the figure.
MORE DATAQTYIDENTIFICATIONNAMETASKSTEP
(a)--WebInspect1
(b)--Upper chordInspect2
(b)--Lower chordInspect3
(c)--FastenersInspect4
(a) Do a detailed inspection of the visible surfaces of the web for any crack.
(b) Do a detailed inspection of the visible surfaces of the chord from LBL 30.0 to RBL 30.0 for any crack
around fastener locations common to the web.
(c) Do a general visual inspection to make sure all fasteners are installed at fastener locations common to
the web and lower chord. Fasteners are expected at the locations shown.
FIGURE 3: STA 320 CROWN FRAME - INSPECTION
(SHEET 4 OF 4)
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2 August 20, 2015
56 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 57

FIGURE 4: DELETED
(SHEET 1 OF 1)
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2 August 20, 2015
57 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 58 (OCR)

BOEING SERVICE BULLETIN 747-53A2784
ALERT  ALERT
This Figure applies only to: Group 1, Configuration 1, 3.
_STA 340
_STA 320
1698747
FIGURE 5: STA 320 CROWN FRAME - WEB INSPECTION
(SHEET 1 OF 5)
Original Issue: August 27, 2009
Revision 2 August 20, 2015  Export Controlled ECCN: 9E991 - BOEING  PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.

### Page 59

FIGURE 5: STA 320 CROWN FRAME - WEB INSPECTION
(SHEET 2 OF 5)
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: August 27, 2009
747-53A2784Revision 2 August 20, 2015
59 of 248
BOEING SERVICE BULLETIN 747-53A2784
ALERTALERT

### Page 60 (OCR)

BOEING SERVICE BULLETIN 747-53A2784
ALERT  ALERT
LBL  6 LOCATIONS  BL O
5 LOCATIONS  7.5
LBL
15.0
6 LOCATIONS
LBL
20.0
5 LOCATIONS  6 LOCATIONS
4 LOCATIONS
A-A
*- REFERENCE FASTENERS
1733669
FIGURE 5: STA 320 CROWN FRAME - WEB INSPECTION
(SHEET 3 OF 5)
Original Issue: August 27, 2009
Revision 2 August 20, 2015  PROPRIETARY - Copyright © Unpublished  Export Controlled ECCN: 9E991 - BOEING  747-53A2784
Work - See page 1 for details.  60 of 248

The text continues at https://openairdocs.org/service-documents/boeing/747-53a2784/file/6a6172e10cd1.md?from=61

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain, except the copies of manufacturers’ service documents, which belong to their rights holders.